Objectives To establish a determination method of niclosamide in drinking water.Methods Niclosamide in drinking water was extracted by butyl acetate/petroleum ether mixture,then stripped by NaOH solution,and the content of niclosamide in NaOH solution was determined by photometry on wavelength 380 nm.Rusults The limit of detection was 0.03 mg/L,the liner correlation coefficient was 0.9995,the RSD was 6.1%,and the average recovery was 97.0%.Conclusions The method was accurate and could be applied for the determination of niclosamide in drinking water.

Objective:To establish a new method for the determination of niclosamide in drinking water by HPLC. Methods:The separation was carried out on an C18 column by using the mobile phase consisting of CH3OH+ H2O(85 + 15). The flow rate was 1. 0 ml/min. Detection was done by DAD at the wavelength of 330 nm. Results:The linearity was obtained in the range of 0. 2 mg /L ~ 25 mg /L,the correlation coefficient was 0. 9999. The limit of detection was 0. 3 μg/L,the rate of recovery was between 95. 02% ~ 103. 9% with RSD less than the reference value 5. Conclusion:This method has good accuracy and precision. This method is suitable for the determination of niclosamide in drinking water.

Objectives To establish a method of detecting the powder of niclosamide ethanolamine salt(PNES) in water by chemiluminescent.Methods The effects of the concentration of luminol,NaOH and HAuCl4 on chemiluminescence were studied with control variable method,and the optimized concentration of luminol,NaOH and HAuCl4 were 0.5 mmol/L,0.05 mol/L and 0.3 mmol/L,respectively.The calibration curve for the determination of PNES was obtained by using a standard solution under optimized conditions.The samples were detected and the recoveries of standard addition were also tested.Results The calibration curve was linear for PNES in the range of 0.1-8.0 mg/L,with the correlation coefficient of 0.999 and the detection limit of 0.07 mg/L.Conclusion This method is simple,rapid,sensitive and feasible for detecting PNES in river water.

Objective:To establish chemiluminescence detection of sulfur dioxide(SO2) in food.Methods:SO2 quantificationally reacts with potassium permanganate,which can decrease the chemiluminescence intensity(CL) of the potassium permanganate-resorcin system,and the decrement of CL is correlated with the concentration of SO2.Results:In optimized condition,the calibration graph is linear in the range of 0.04～40.00 mg /L,and the limit of detection(LOD) is 0.03 mg /L(S /N=3).Conclusion:The proposed method can detecet SO2 in food.

目的探索并开发现场检测氯硝柳胺浓度的方法和仪器。方法在实验室条件优化和氯硝柳胺测定的基础上建立了氯硝柳胺分光光度计现场测定方法,并研发现场检测仪。结果该检测氯硝柳胺浓度方法的线性范围为0～8g/m3,检测限为0.015g/m3。现场检测仪规格为2.5cm×9cm×24cm。结论该检测方法灵敏度较高,所研发的光度计设计合理且使用方便,适于在现场推广应用。

Objective To study the method and conditions of determination of niclosamide in water. Methods Niclosamide was extracted by mixed extractent, then striped by NaOH. Niclosamide in NaOH solution was determined with dual-wavelength photometry. Results The recovery of niclosamide was 93%. The linear ranger was 0-4. 0 g/m3 and the detectable limit for niclosamide was 0. 042 7 g/m3. The apparent molar absorptivity was 1. 26 ×105 L/(mol·cm). Conclusion Extraction photometry is suitable for determination of niclosamide in water in the field.

近年来,许多不法商贩在一些食品生产加工过程中加入甲醛或甲醛*次硫酸氢钠(吊白块),以增加产量或改善外观、口感等.甲醛对人体有害,世界卫生组织和欧共体都将之列为致癌物[1,2].因此,现场快速检测甲醛是保障食品安全的重要手段.卫生部建议的检测甲醛方法为蒸馏-乙酰丙酮法.此法灵敏度虽高,但需蒸馏,不适应现场快速检测,并且在酸性条件下蒸馏有时会产生"分析本底"形成假阳性[3];而吊白块分解产生的SO2在微酸性条件下与甲醛结合会使测定值偏低[4].本实验通过改进,建立起一种现场快速准确的检测食品中甲醛含量的方法.该法具有较强的选择性,不需要蒸馏,能避免分析过程中的一些干扰,可用于现场快速检测甲醛.

呋喃丹是一种内吸性杀虫剂.因其残留毒性高,口服易急性中毒,是蔬菜生产过程是禁用的农药.但个别错误施用的现象时有发生,给土壤和蔬菜带来了污染.因此,研究呋喃丹在土壤中残留的分析方法具有重要意义.呋喃丹属氨基甲酸酯类农药,可用农药残留快速测定法(酶抑制法)测定[1].但检出限高且不能准确定量测定.国家标准采用色谱法测定[2],但样品处理和仪器要求高,不能用于快速检测.本文采用光度法测呋喃丹的含量,与上述方法相比,具有简便、快速、准确的特点.

GF-AAS method was applied to the determination of microamounts of lead in salt-containing flavourings without the necessity of sample-pretreatment. Palladium chloride was added to the dilute nitric acid sample solution as matrix modifier. The background interference due to the presence of macroamounts of sodium chloride was effectively eliminated by the use of Zeeman effect technique. Recoveries between 88.0%～99.0% were obtained. RSD′s obtained by 10 successive determinations were less than 5.0%. Working conditions of instrument are given.

利用Ag+对一些显色反应的催化作用,可以建立吸光光度法测定痕量银的方法已有报道[1,2].本文对银催化亚铁氰化钾与邻二氮菲显色法测银的方法[1]进行了改进,主要原理是Ag+可以催化亚铁氰化钾的分解,分解出的亚铁离子再与邻二氮菲生成桔红色的配合物,配合物的最大吸收波长λmax=508nm,摩尔吸光系数ε=1.1×104L·mol-1·cm-1,方法有很高的灵敏度.但亚铁氰化钾的分解,必须在强酸性条件下,且为可逆反应,而生成的HCN又有挥发性,方法的稳定性较差.本文加入甲醛作为氰氢酸的捕捉剂,可使亚铁氰化钾分解反应更完全,使测定能在较高pH条件下也能进行.本法灵敏度、稳定性都比改进前有所提高.

蔬菜的卫生质理直接关系到人们的身体健康,为确保蔬菜的卫生安全,扬州市于1996年创建了第一个无公害蔬菜生六基地,并从600多亩发展到了3000金亩.

作者根据吸收光谱具有的全息性,首次提出采用波长位移,选择适当的入射光波长,吸光值通过简单计算,同时测定多组分混合物中成分的方法.文中以测定饮料中食用合成色素为例,对方法的可行性、实用性进行了验证,结果表明,此法为吸光光度法提供了又一种实用的分析技术.

随着科学的发展,低浓度铅对健康的危害日益被人们所认识,众多报道[1～3]表明儿童机体对铅毒性的敏感性较高.为了解我市儿童血铅水平,从而更好地保护儿童身体健康.我们于1997～1998年对扬州市480名小学生进行了血铅水平及其影响因素的调查.